Brake head guide



Oct. 14-, 1958 B. J, cGUlRE 2,856,033

. BRAKE HEAD GUIDE Filed July 22, 1953 2 Sheets-Sheet 1 IN V EN TOR.

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Oct. 14, 1958 B. J. MCGUIRE BRAKE HEAD GUIDE 2 Sheets-Sheet 2 Filed July 22, 195:5 1

INVENTOR.

fiamwzcl nited States Patent BRAKE HEAD GUIDE Bernard J. McGuire, Chicago, 111., assignor to American gteel Foundries, Chicago, 111., a corporation of New ersey Application July 22, 1953, Serial No. 369,561

6 Claims. (Cl. 188-73) This invention relates to a novel arrangement operative to maintain a lever carried brake head in correct position to engage an associated friction surface.

A general object of the invention is to provide an arrangement that will result in even wear on a friction shoe surface during braking engagement of said shoe.

Another general object of the invention is to provide a novel arrangement to maintain parallelism between a friction shoe face and an associated engaged friction surface.

A further object of the invention is to provide a novel arrangement operative to pivot an associated friction shoe on its carrying brake lever in response to movement of the lever.

A more specific object of the invention is to incorporate in said novel arrangement an intermediate member pivoted to the brake lever and engaging on its opposite ends the friction shoe carrying brake head and a relative fixed lever mounting block.

It is a further object of the invention to provide slotted engagement between said intermediate member and said brake head and fixed mounting block respectively.

It is another specific object of the invention to provide pin and slot arrangements to accommodate the mentioned engagements between the intermediate member and the brake head and mounting block respectively.

Still another object of the invention is to provide geared engagement between the intermediate member and the brake head and mounting block respectively.

These and other objects of the invention will become apparent in the course of the following description and from an examination of the concerned drawings, where- Figure l is a fragmentary generally diagrammatic sketch of a typical brake arrangement to which the invention may be applied;

Figure 2 is a fragmentary sectional plan view of the brake arrangement of Figure 1, showing in detail the application of the invention to said brake arrangement;

Figure 3 is a fragmentary side elevational view taken substantially along line 33 of Figure 2;

Figure 4 is another fragmentary view similar to Figure 3 of a modified form of the invention, and

Figure 5 is a fragmentary view of the modification shown in Figure 4 taken from below as seen in Figure 4.

Describing the invention in detail and referring first to Figure 1, wherein is illustrated a conventional quarter section of a railway car truck having a side frame 2 supported in the usual manner by a wheel and axle assembly 4. The assembly 4 incorporates a rotor 6 rigidly secured to said assembly and rotatable therewith. Adjacent the assembly the frame presents a transom 8 to which may be mounted in any usual or convenient manner a brake housing 10. Projecting from one end of the brake housing, brake levers 12, 12 are seen to extend longitudinally of the truck and embrace the rotor 6.

the brake head assemblies 14, 14.

ice

Referring now to Figure2 which shows in detail and in horizontal section a portion of the braking arrangement diagrammatically shown in Figure 1. noted that within the brake housing 10 there is positioned a mounting block 16, said mounting block being pivoted on an axis 18 which extends longitudinally of the truck. Secured to the opposite wings of the mounting block 16 are the brake levers 12, only one lever being shown in Figure 2 inasmuch as the arrangement is duplicated on the opposite side of the brake housing 10. The brake lever 12 is pivotally mounted to the mounting block 16 by means of a pivotal pin 20 as can bereadily seen in Figures 2 and3. The brake lever 12 extends rearwardly to a point where operative connection (not shown) is made with an actuating cylinder (not shown) as is conventionally accomplished in the art. ally, the brake lever 12 extends forwardly to a point whereat a brake head assembly 14 is pivotally mounted. It will be noted that an opening 24 is provided in the forward face of the brake housing 10 to accommodate the forward extension of the brake lever 12.

The brake head assembly 14 consists of a brake head 26 having on one side thereof the extended lugs 28 and 30. The lugs 28 and 30 are vertically spaced receiving therebetween the forward extremity of the brakelever 12, the pivotal connection between the brake lever 12 and the brake shoe 26 being accomplished by a pin 23 being received within vertically aligned apertures in the lugs 28 and 30 and the brake lever 12; Additionally, the brake head may mount a conventional nonrattling device indicated generally at 32, said device comprising an arm secured to the underside of the brake lever 12 and having a downwardly and horizontally extending segment 34 having a hole 36 formed therein to receive said pin 23. A spring 38 is interposed between the head 40- of the pin 23 and the portion 34 of the nonrattling device 32, the spring serving to maintain the brake head firmly but resiliently on the end of the brake lever 12.

The brake head assembly 14 also comprises a friction shoe 42 conventionally afiixed to the side of the brake head 26 opposite the lugs 28 and 30. The friction shoe 42 presents a friction surface 44 which is operative to engage a rotating friction surface 46 of the adjacent rotor 6 during the pivotal action of the brake lever 12 as is well understood by those skilled in the art.

Considering now the particulardevice employed to maintain parallelism between the surfaces 44 and 46, attention is directed to the upper brake head lug 28. As is best seen in Figure 2, the upper lug 28 presents a rearwardly extending slot 48 immediately above the brake lever 12. Examining the mounting block 16 it will be seen that another slot 50 is presented by said mounting block immediately above the brake lever 12 and at a point directly forward of the pivot 20 which connects the brake lever 12 to the mounting block 16. An intermediate lever member or gear 52 is pivotally secured to the brake lever 12 at a point preferably equally spaced from the axes of pivots 20 and 23, a pin 54 serving to pivotally mount said intermediate lever to the brake lever. The intermediate lever 52 comprises oppositely extending arms 56, 56, said arms being respectively received within the slot 50 of the mounting block 16 and the slot 48 of the brake head lug 28. 1

In the arrangement just described it should be apparent that as the brake lever 12 is urged by its actuating means (not shown) to rotate counerclockwise as seen in Figure 2 and thereby urging the brake shoe surface 44 to engage the rotor surface 46, the link connection offered by the intermediate lever 52 between the :mounting block 16 and the upper lug 28 will urge the brake head assembly 14 to pivot in a clockwise direction about It will be,

Additionits axis of pivot 23. Thus as the brake shoe is carried into engagement with the rotor, the arrangement descrlbed urges the brake head assembly to rotate clockwise and :hence bring-the .shjoesurface 544 into full: flat engagementwith the .surfacet46 of the rotor. Conversely, as .the lever 12 ;-moves in a clockwise direction during disengagement of'the shoe from the rotor, the intermediate .lever 52; urges -the head assembly 14 to rotate .in a

in what is widely-known as-;the standard composite involutegeansystem, either-14% or which ever may be deemedappropriate to the particular PPlication. It should-,also be noted thattany given gear form may-be employed other than the standard composite system designated. The'employing of-thegear form in the slots ;48.and.50 and the .arms 6 justifies the designation :of the intermediate lever-52 as'aggearlever. A particular advantage in employingsaidgearsystem is that a smooth and more even action is achieved during pivotal movement of the brake lever 12 thisjimproved action being attributable to the reductionof-sliding-contact'to a minimumzand to the resultingrolling-action of the'engaged toothforms during the-pivotal action above described of the lever '12.

,Attention is nowdirectedtwFigures 4-and5 wherein is-illustrateda modified embodiment'of the invention. However, the brake-housing, brake lever-and brake shoe assembly employed. in this embodiment is substantially identical-with that heretofore described, the identical features being designated by the numerals heretofore employed. Additionallyr he embodiments -of Figures 4 and 5 employ an intermediate lever 60 pivotally secured to the brake lever 12 in a manner :similar to that of the embodiment heretofore described fbllt'Oll' the lower side of the lever. The lever60'cornprises oppositely'extending arms 6,2, 62. It will-be noted that the lower brake headlug ;;is employed't-o act-in-poncert with the intermediate lever-6,0,,said lower brakeyhead lug 30 having on its rearwardlydirected facearigidly connected U-shaped lug 64 which'defines a-U.slot.-65 facing rearwardlyof the brake head assembly. The brake lever mounting block 16 hasrigidly orintegrally affixed to its forward face another u-shaped lug 66, said ,U-shaped lug 66 presenting a forwardly facing -U slot 68. At opposite ends of the intermediate lever 60, that is, on the extremities of'the arms62, 62, there are vertically extended pins 70, 70, said pins beingrespectively received within the U-shaped slots 65 and-68 presented by the respective lugs 64and.66. Thefact that the lever and slot arrangement-of the.embodimentofFigures 4 and 5 is mounted on the lower side of said lever offers an additional ad- .vantagein that foreignmatter will not become packed or retained within theslots65 and 68,.thus avoiding possible malfunction ofthe arrangement. .It is alsobelieved within the scope of the invention disclosed .to mount either of the illustrated embodimentsron either the upper or lowerside of the: brake lever.

"The operation of the arrangementof Figures 4 and 5 is'substantially similar to that as heretofore described for the previous embodiment. 'Itshould be noted, however, that as the'brake lever '12'is rotated the engagementbetween the pins 70 and the slots 65 and 68 results in a'sliding action, the pins sliding along the surfaces of the respective slots. However, in other respects the Iactionof this embodiment is identical with that hereto- .fore described .andthe .resultingparallelism of t the. brake shoe surface 44 and the rotor surface 46 is maintained throughout all angular positions of the brake lever 12.

Thus it will be seen that in the invention disclosed and described there is provided a novel arrangement whereby parallelism between a friction shoe face and an associated engaged friction surface is always maintained thus ensuring a positive and even Wear on the friction shoe surface during braking engagement of the shoe with the related friction surface.

I claim:

1. In a brake arrangement, a movable friction surface, a brake head assembly comprising a brake head and a brake shoe, said brake shoe having a friction surface complementally engageable with said movable friction surface, a lug on said brake head remote from said shoe, said lug having a slot therein, a brake lever pivotally carrying .said assembly, a mounting member 'pivotally carrying said brake lever, said mounting member having a slot therein, and an intermediate lever pivotally connected to -said brake lever intermediate said mounting member and assembly, the opposite ends of said intermediate lever being disposed within' and engaging-"said slots.

2. LInla brake arrangement, a movable friction surface, a brakeheadassembly having abrake shoe with a friction surface thereon complementally engageable with the first-mentioned frictionsurface, a brake lever pivotally carrying said assembly, a mounting member-pivotally carrying said lever, a slot inthe mounting member, a slot in the assembly, and an intermediate lever-pivotally carried by said brake lever between the assembly and mounting member, said intermediatelever/having oppositely extending-arms, one of said arms pivotally engaging said assembly slot, the other of said arms pivotally engaging said mounting member slot.

3. In a brake arrangement, a frictionsurfacc, a friction shoe assembly comprising a friction shoe havinga surface engageable'with-the first-mentioned surface, a:lever pivotally connected at one-end thereof tojsaid assembly, a mounting member pivotally connectedito saidlever intermediate the ends thereof, a slot-in said'mountingmembet, a slot in said assembly, and means :pivot'ally connected to saidlever intermediate the assembly and mounting member pivotal connections, :said means comprising an intermediate lever extending longitudinally of said first-mentioned lever and abuttably 'enga-gingsaid mounting member slot and assembly .slot, :sai'd intermediate lever being operative to maintain'full face engagement of the shoe friction surface with the first-mentioned friction surface.

4. In a brake arrangement, a rotatable frictionisurface, a brake shoe assembly comprising a shoe having a friction surface engageable with the rotatable surface, an actuator pivotally connected to the assembly along a pivotal axis, said actuator being operative to move said shoe surface into and out of engagementwith said rotatable surface, amounting member :pivotally connected to the-actuatoralonganother pivotal axis, said pivotal axes bein disposed substantially parallel to each other, and means comprisingan intermediateactuator pivotally connected to'said first-mentioned actuator-alongan axis disposedbetween and substantially parallel to said first-men- 'tioned axes, said means having slotted engagement with "said brake shoe assembly and mounting member.

5. 'In a brake arrangemenha movable friction surface, a brake head assembly havinga brake shoe with a friction surfacethereon engageable with said movable surface, a brake lever pivotally connected to said assembly along a pivotal axis, a mounting member pivctally connected'to :the lever along a pivotal axis parallel to the first-men- .tioned axis, a lug on said assembly, a slot in said lug facing towards said mounting member, a slot in said mounting member, said last-mentioned slot facing towards said assembly, an intermediatelever:pivotally connected to said brake lever along an axis disposed intermediate .said assembly and mounting member, said last-mentioned axis being equi-distantly spaced from and parallel to the first-mentioned axes, and rigid arms on said intermediate lever, one of said arms engaging the mounting member slot, the other of said arms engaging the assembly slot.

6. In a brake arrangement, a rotatable friction surface, a brake shoe assembly comprising a brake head and a brake shoe, said shoe having a friction surface engageable with said rotatable surface, a brake lever pivotally connected to said brake head to actuate the assembly, a mounting block pivotally connected to the lever, a slot in the mounting block, a slot in the brake head, an intermediate lever pivotally connected to the brake lever intermediate the block and assembly, a pair of arms on said intermediate lever, one of said arms extending toward and engaging said block slot, the other of said arms extending towards and engaging the brake head slot, the slots in the block and brake head each defining a standard gear form, and each of said arms defining a standard gear form.

References Cited in the file of this patent UNITED STATES PATENTS 2,348,078 Ledwinka May 2, 1944 2,436,136 Baselt Feb. 17, 1948 2,661,818 Tack Dec. 8, 1953 

